1. Technical Field
The present disclosure relates to a seat, and more particularly to a seat capable of reducing a load imposed on a temperature control means of a seat heater.
2. Related Art
Heretofore, at a low atmospheric temperature for example in winter, there has been the problem that, when a person sits on a seat, the seat temperature is low and does not feel comfortable. In view of this point, there has been developed a technique of disposing a seat heater in the seat. By disposing a seat heater not only in a seating portion (seat cushion surface portion) against which the hip of a sitting person comes into abutment but also in a backrest surface which bears the waist of the sitting person, the feeling when the person sits thereon is improved.
As noted above, the seat heater is provided, for example, for the retention of heat and for the prevention of freezing. The seat heater is a planar heating unit capable of heating the seat by means of a heating wire embedded in the seat cushion surface portion of the seat and thereby the feeling when a person sits thereon is improved.
Examples of seats for which such a seat heater is required are seats disposed in sofas, massage chairs and vehicles such as automobiles, motorcycles and snowmobiles. Particularly, in straddling type vehicles such as motorcycles and snowmobiles, riders are directly influenced by environmental conditions such as temperature and wind, unlike the seats used in the other cases, and therefore especially in cold districts, the seat heater is very important. With a vehicle seat heater provided not only in the seat surface on which a person sits but also in the backrest surface which bears the waist of the sitting person, the feeling when the person sits thereon is improved.
In Japanese Patent Application Publication No. 2003-127947 there is disclosed a technique such that, in a seat having a cushion member covered with a skin material, a tape is disposed on the surface of the skin material and a cord type or film type heater (seat heater) is disposed between the tape and the skin material.
In Japanese Patent Application Publication No. 2005-279070 there is disclosed a technique such that, in a seat comprising a front seat and a backrest for bearing the waist of a sitting person on a rear side of a vehicle body with respect to the front seat, a seat heater for the front seat and a seat heater for the backrest are each disposed on an upper surface of a cushion member and covered with a skin material. Heater wires are disposed meanderingly in the longitudinal direction of the vehicle body so as to be substantially right-left symmetric on both sides of a nearly central part of a base cloth corresponding to a longitudinally extending central part of the vehicle body.